Another anomaly in Silverlight

I can not get a TextBlock to be HitTest'd. If I change it to TextBox, HitTest works. But not on a TextBlock, not even with IsHitTestVisible to true.

Can not capture mouse in Silverlight ComboBox

I ran through a problem in implementing Drag and Drop in Silverlight. While it works for button, checkbox, textblocks, etc., CaptureMouse always returns false for a ComboBox. Weird...